AB1633 PREVALENCE TREND OF EGPA AND ANNUAL CHANGES IN ORAL CORTICOSTEROID USE BY PATIENTS WITH EGPA FOLLOWING MEPOLIZUMAB AVAILABILITY IN JAPAN
Authors: K. E. Sada, T. Suzuki, S. Joksaite, S. Ju, G. Mu, J. Logie, J. Hwee, H. Kunishige, T. Ishii, A. Adlak, H. Vadlamudi, R. Alfonso-Cristancho
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Treatment of eosinophilic granulomatosis with polyangiitis (EGPA) relies predominantly on corticosteroids which are associated with significant adverse effects when used long-term. Therefore, alternative corticosteroid-sparing therapies are needed. Mepolizumab specifically targets IL-5, a key driver of eosinophilic inflammation, and was approved in Japan for the treatment of EGPA in 2018. <h3>Objectives</h3> To describe the prevalence of EGPA over time and changes in OCS daily dose used by patients with EGPA in Japan. <h3>Methods</h3> This retrospective study used the Japanese health insurer claims database (JMDC) to describe EGPA prevalence 2005–2020. The Japanese hospital database (Medical Data Vision [MDV]) was used to describe annual mean daily doses of OCS used by patients with EGPA, comorbidities associated with OCS use, and relapse rates of EGPA 2010–2020. Patients with a record of EGPA in the year of interest and a record of allergic rhinitis, eosinophilic chronic sinusitis or asthma were included, excluding those with granulomatosis with polyangiitis and microscopic polyangiitis, before or during the year of interest. Relapse was assessed in patients who revisited the hospital and was defined as initiation of new OCS (non-OCS users), doubling of existing OCS daily dose, or use of injectable corticosteroid pulse therapy among patients who received continuous treatment from the previous year or earlier. A sub-analysis of the JMDC database assessed OCS daily dose used by patients with EGPA who initiated treatment with mepolizumab 300 mg 2018–2020. <h3>Results</h3> From the JMDC database, ~7.3 million subscribers were included for EGPA prevalence estimations. The reported annual crude prevalence of EGPA increased from 4.2 per million in 2005 to 58.6 per million in 2020 with a greater prevalence in older age groups (prevalence per million in 2020: &lt;18 years: 7.5; 18–39 years: 42.5; 40–64 years: 93.1; and 65–74 years: 181.3). From the MDV database, 1870 patients with EGPA were included in 2020, 59.9% of whom were female, and 5.2% were aged 18–39 years, 36.4% 40–64 years, 30.6% 65–74 years, and 27.4% ≥75 years. Mepolizumab was prescribed for EGPA in &lt;1.0% of patients before 2017 and use increased over time from 2.4% in 2017 to 20.6% in 2020. OCS remained the most prescribed treatment through 2020 (83.4%), with azathioprine used by 17.8% and injectable corticosteroids by 15.3%. Proportion of patients that used zero/low prednisolone-equivalent daily OCS doses increased from 2017 (0 mg: 13.6%; &gt;0–≤5 mg: 41.8%) to 2020 (0 mg: 16.6%; &gt;0–≤5 mg: 42.1%); while those who used &gt;10 mg decreased from 2017 (11.9%) to 2020 (10.3%; Figure 1). Median OCS daily dose was 4.9–7.7 mg between 2010 and 2016, and 4.5–4.8 mg between 2017 and 2020, with the lowest dose in 2020 (4.5 mg (IQR 1.6–6.8)). Proportion of EGPA patients with comorbidities related to corticosteroids remained relatively consistent over time, except for infectious disease which showed a decrease from 94.4% in 2010 to 70.9% in 2020. Proportion of patients with other comorbidities in 2020 were dyslipidemia (37.6%), hypertension (33.6%), diabetes (23.4%), fracture (12.3%), mood disorders (10.1%), and cataract (7.2%). Of 1717 revisiting patients in 2020, 41.6% relapsed, which was 5.0–37.4% lower than in the years 2010–2019. In the subgroup of 24 patients new to mepolizumab from the JMDC database, the prednisolone-equivalent mean (SD) daily dose decreased from 11.2 mg (7.1) in the 90 days before to 4.3 mg (2.7) in the 4th quarter after mepolizumab initiation. <h3>Conclusion</h3> Prevalence of EGPA in Japan showed a continued increase through 2020, suggesting improved recognition of this disease. A decrease in OCS daily dosing was observed after mepolizumab was introduced in 2018, yet further improvement in EGPA management is warranted. <h3>References</h3> N/A. <h3>Funding</h3> GSK (218083/218084). <h3>Acknowledgements</h3> N/A. <h3>Disclosure of Interests</h3> KEN-EI SADA Speakers bureau: GSK, Grant/research support from: Pfizer Inc, Takeo Suzuki Employee of: GSK, Sandra Joksaite Shareholder of: GSK, Employee of: GSK, Shinyoung Ju Shareholder of: GSK, Employee of: GSK, George Mu Shareholder of: GSK, Employee of: GSK, John Logie Shareholder of: GSK, Employee of: GSK, Jeremiah Hwee Shareholder of: GSK, Employee of: GSK, Hideaki Kunishige Shareholder of: GSK, Employee of: GSK, Takeo Ishii Shareholder of: GSK, Employee of: GSK, Amit Adlak Shareholder of: GSK, Employee of: GSK, Harini Vadlamudi Employee of: GSK, Rafael Alfonso-Cristancho Shareholder of: GSK, Employee of: GSK.